https://www.hackerrank.com/challenges/fp-update-list/problem?isFullScreen=true

map_list_to_abs.ex

defmodule Ab do
  def abs(x) when x < 0, do: x * -1
  def abs(x), do: x
end

defmodule Solution do
  IO.read(:all)
  |> String.split
  |> Enum.map(&String.to_integer/1)
  |> Enum.map(&Ab.abs/1)
  |> Enum.each(&IO.puts/1)
end